CN-122008254-A - Robot grabbing anti-collision control method and system for automatic production line

CN122008254ACN 122008254 ACN122008254 ACN 122008254ACN-122008254-A

Abstract

The application belongs to the field of automatic production line control, and in particular relates to a robot grabbing anti-collision control method and system for an automatic production line, wherein the method comprises the steps of responding to a trigger signal of a robot entering a grabbing track, continuously collecting multi-frame two-dimensional code images in the process that a robot gripper moves towards a workpiece, and analyzing to obtain first workpiece model data; the method comprises the steps of triggering acquisition again at the moment that a gripper contacts a workpiece, analyzing the workpiece model data to obtain second workpiece model data, respectively carrying out double comparison on the workpiece model data obtained through analysis and preset target model data, allowing a robot to lift and transfer the workpiece if the double comparison is uniform, immediately executing an emergency stop program if any comparison is inconsistent, interrupting the grabbing program through a software instruction, triggering an audible and visual alarm, outputting a physical isolation signal, cutting off a safety relay coil connected in series in a grabbing power loop, and enabling the robot to keep the current safety posture to prevent collision accidents.

Inventors

ZUO KAI
SHI JUN
LIU XUEKAI
LI ZONGQIANG
LI AN
ZHANG GUANGLU
Lou Fangzheng
XU DEBING
YANG JIAN
REN LIWEI
FENG GUOMING
JIA HUISHU

Assignees

济南二机床集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (10)

1. A robot gripping anti-collision control method for an automatic production line, which is applied to a robot gripping system controlled by a line programmable logic controller, and is characterized by comprising the following steps: s1, when a trigger signal of a robot entering a grabbing track is received, a line body programmable logic controller sends a starting instruction to a code scanning gun, and the code scanning gun continuously acquires multi-frame two-dimensional code images at preset frequency in the process that a robot gripper moves to a workpiece in a material frame; S2, analyzing the multi-frame images in real time, extracting clear and readable two-dimensional code information frames, and analyzing to obtain first workpiece model data; S3, triggering and collecting again by the code scanning gun at the moment that the robot gripper contacts and grabs the workpiece, acquiring a two-dimensional code image at the grabbing moment, and analyzing to obtain second workpiece model data; S4, performing double comparison on the first workpiece model data and the second workpiece model data with target model data preset by the touch screen respectively; S5, if the double comparison results are consistent, sending a lifting permission signal to a robot control system, and controlling the robot to take out the workpiece from the material frame and transfer the workpiece to a processing station; S6, if any comparison result is inconsistent, immediately executing an emergency stop program: interrupting a robot grabbing program through a software instruction and triggering an audible and visual alarm; The physical isolation signal is output through an independent hard wire IO, and the safety relay coil connected in series in the robot grabbing power loop is cut off, so that the robot is kept in the current safety posture, and collision accidents are prevented.
2. The robot gripping anti-collision control method for an automatic production line according to claim 1, wherein the trigger signal of the robot entering the gripping track in S1 is generated by a dual-confirmation mechanism of cooperation of software and hardware: Receiving a path planning completion signal fed back by a robot control system, and confirming that the robot has generated a complete grabbing motion track; the second condition is that a proximity switch detection signal installed at the starting point of the grabbing track is received, and the fact that the robot physically reaches a preset triggering position is confirmed; and generating a trigger signal for the robot to enter the grabbing track only when the first condition and the second condition are simultaneously met.
3. The robot gripping anti-collision control method for an automatic production line according to claim 2, wherein in S2, real-time analysis is performed on a multi-frame image, a clearly readable two-dimensional code information frame is extracted, and first workpiece model data is obtained by analysis, specifically comprising: S21, performing two-dimensional code region detection and positioning on the acquired continuous image frames; S22, performing quality evaluation on the positioned two-dimensional code area, and screening out effective image frames meeting decoding requirements; s23, performing image optimization processing on the screened effective image frames to obtain a decodable two-dimensional code image; S24, decoding the optimized two-dimensional code image, and extracting first workpiece model data.
4. The method for controlling the robot grabbing anti-collision in the automatic production line according to claim 3, wherein in S22, the quality evaluation is performed on the located two-dimensional code area, the effective image frames meeting the decoding requirement are screened out, and the method is realized by adopting a multi-frame fusion mode, and specifically comprises the following steps: S221, calculating the comprehensive quality score of each frame of image, wherein the comprehensive quality score at least comprises a definition index, a contrast index and a motion ambiguity index; s222, selecting an image of K frames before ranking as a candidate effective frame according to the comprehensive quality score, wherein K is a preset integer greater than 1; And S23, performing image optimization processing on the screened effective image frames, wherein the method specifically comprises the steps of performing image registration and pixel-level fusion on the K frame candidate effective frames to generate a fused two-dimensional code image.
5. The robot gripping anti-collision control method for an automatic production line according to claim 3, wherein in S22, quality evaluation is performed on the located two-dimensional code area, effective image frames meeting decoding requirements are screened out, and in S23, image optimization processing is performed on the screened effective image frames, and the method is implemented by adopting an adaptive strategy: Directly enhancing and decoding the single frame image with highest quality; if the single frame decoding fails, starting a multi-frame fusion mode, carrying out image registration and pixel-level fusion on multi-frame images, and then attempting decoding again.
6. The robot gripping anti-collision control method for an automatic production line according to claim 1, wherein in S3, at the moment when the robot gripper contacts and grips the workpiece, triggering the code scanning gun to acquire and analyze again to obtain second workpiece model data, and realizing by adopting a multi-source signal fusion triggering mode, specifically comprising: S31a, monitoring a force feedback signal when the gripper contacts with a workpiece in real time through a force sensor arranged on the robot gripper, and when the force feedback signal exceeds a preset threshold value, judging that the gripping instant arrives, and generating a first trigger signal; s32a, simultaneously receiving a grabbing action execution state signal fed back by a robot control system, and generating a second trigger signal when the grabbing action execution state signal indicates that the grippers reach the grabbing position and the grippers start to be closed; s33a, performing logical AND operation on the first trigger signal and the second trigger signal, and generating a final grabbing instant trigger instruction only when the two signals are valid simultaneously; S34a, responding to the grabbing instant triggering instruction, controlling the code scanning gun to acquire single-frame or multi-frame images, and starting the light supplementing device at the same time, so as to ensure that a clear two-dimensional code image is captured at the moment that the grabbing hand contacts a workpiece; s35a, carrying out two-dimensional code region detection on the acquired grabbing instant image, and combining the two-dimensional code position priori information acquired in the S2 stage to quickly locate the two-dimensional code region in the image; S36a, performing targeted image enhancement processing on the positioned two-dimensional code area, and compensating motion blur and illumination change generated by contact moment; s37a, decoding the processed two-dimensional code image, extracting workpiece model information, and outputting the workpiece model information as second workpiece model data after format verification.
7. The robot gripping anti-collision control method for an automatic production line according to claim 1, wherein in S3, at the moment when the robot gripper contacts and grips the workpiece, triggering the code scanning gun to acquire and analyze again to obtain second workpiece model data, and the method is implemented by adopting a multi-source signal comprehensive judgment mode, and specifically comprises the following steps: s31b, collecting the states of at least two trigger signal sources in real time: a force sense sensor signal for detecting a force feedback change when the gripper is in contact with the workpiece; A position sensor signal for detecting whether the gripper reaches a preset gripping position; a robot control system status signal for monitoring the progress of execution of the grasping action; A jaw opening sensor signal for monitoring a degree of jaw closure; S32b, comprehensively judging the multi-source signals according to preset trigger logic, and generating a trigger instruction when the judgment condition of the grabbing moment is met, wherein the trigger logic comprises that the force sensor signal exceeds a set threshold value and the opening sensor signal of the clamping jaw starts to change, or the force sensor signal exceeds the set threshold value and the robot control system feeds back that the grabbing action is executed to a preset stage; S33b, responding to the generated trigger instruction, controlling the code scanning gun to complete image acquisition, and ensuring that the acquisition time is strictly synchronous with the grabbing moment; s34b, carrying out two-dimensional code identification and decoding on the acquired image, and outputting second workpiece model data.
8. The robot gripping anti-collision control method for an automatic production line according to claim 1, wherein in S3, at the moment when the robot gripper contacts and grips the workpiece, triggering the code scanning gun to acquire and analyze again to obtain second workpiece model data, and implementing by adopting a pre-judging triggering strategy to overcome the problem that the gripper shields the two-dimensional code, specifically comprising: s31c, dynamically calculating the residual time required by the hand grip to contact the workpiece according to the current movement speed and the residual movement distance of the robot ; S32c based on delay time of code scanning gun system Setting an early trigger threshold , wherein, Is a preset safety margin; S33c, real-time monitoring When (when) ≤ When the two-dimensional code is not shielded by the hand grip, the hand grip is triggered to capture images before contacting the workpiece, so that shooting is completed in a window period when the two-dimensional code is not shielded by the hand grip; S34c, carrying out two-dimensional code identification on the acquired image, and analyzing to obtain second workpiece model data.
9. The robot gripping anti-collision control method for an automatic production line according to claim 1, wherein in S3, at the moment when the robot gripper contacts and grips the workpiece, triggering the code scanning gun to acquire and analyze again to obtain second workpiece model data, and the method is implemented in a two-camera cooperative mode, and specifically comprises the following steps: s31d, arranging a first code scanning gun and a second code scanning gun on the robot gripper, wherein the first code scanning gun faces the front direction of the workpiece, and the second code scanning gun faces the side surface or the oblique direction of the workpiece so as to cover two-dimensional code positions with different angles; S32d, when the grabbing moment is detected to be reached, synchronously triggering the first code scanning gun and the second code scanning gun to acquire images at the same time, and acquiring at least two grabbing moment images with different visual angles; s33d, respectively carrying out two-dimensional code region detection on the two images with different visual angles; s34d, executing a corresponding decoding strategy according to the detection result: If any image successfully detects the two-dimensional code, decoding is carried out by preferentially adopting the image to obtain a first candidate result; If two images detect two-dimensional codes but the decoding results are inconsistent, selecting a decoding result with higher quality according to an image quality evaluation index to obtain a first candidate result; If the two images cannot be independently decoded, performing view fusion processing on the two images to generate a fused two-dimensional code image, and decoding the fused two-dimensional code image to obtain a first candidate result; And S35d, performing format verification on the first candidate result, and outputting the first candidate result as second workpiece model data after verification is passed.
10. A robotic grasping collision avoidance control system for use in an automated production line, comprising: the touch screen man-machine interface module is used for presetting target model data required by the current production task and displaying production state and alarm information; The robot grabbing module comprises a robot with multiple degrees of freedom and a code scanning gun arranged at the execution tail end of the robot gripper, wherein the robot is used for executing grabbing track movement, and the code scanning gun is used for collecting two-dimensional code images on a workpiece in the moving process and grabbing moment of the robot; The signal acquisition module comprises a proximity switch arranged at the starting point of the grabbing track, a force sensor arranged on the robot grab and a control system interface for monitoring the state of the robot, and is used for generating a trigger signal and a state signal; The line body programmable logic controller module is respectively connected with the touch screen man-machine interface module, the robot grabbing module and the signal acquisition module and is used for generating a trigger signal of the robot entering the grabbing track and a trigger signal of the grabbing moment according to the multi-source signals acquired by the signal acquisition module; analyzing a multi-frame two-dimensional code image acquired by a code scanning gun in real time, extracting a clear and readable two-dimensional code information frame, analyzing to obtain first workpiece model data and second workpiece model data, respectively carrying out double comparison on the first workpiece model data and the second workpiece model data with target model data preset by a touch screen to generate a comparison result signal, and sending an allowable lifting signal or an emergency stop instruction to a robot grabbing module according to the comparison result signal; The safety execution module comprises a safety relay which is connected in series in a robot grabbing power loop, and the safety relay is controlled by a wire programmable logic controller module through independent hard wire IO output and is used for physically cutting off a robot grabbing power source when in emergency stop; And the alarm module is connected with the wire body programmable logic controller module and is used for triggering an audible and visual alarm when the emergency stop occurs.

Description

Robot grabbing anti-collision control method and system for automatic production line Technical Field The application relates to the technical field of automatic production line control, in particular to a robot grabbing anti-collision control method and system for an automatic production line. Background Along with the transformation of the manufacturing industry to a small-batch and multi-variety production mode, one automatic production line is often required to be compatible with mixed line production of a plurality of workpieces with different types. In this production mode, the robot gripping stations on the production line are typically prepared by a human or AGV trolley. However, in the actual production process, due to human negligence or management loopholes, the situation that other types of workpieces are mixed in the feeding material frame often occurs. When a workpiece which is not matched with the current production task is mixed in the material frame, the conventional error proofing system generally adopts a single code scanning verification mode, namely a code scanning gun is arranged at a fixed position, two-dimensional code information is read when the workpiece is transported to the position and is compared with a preset model, and if the two-dimensional code information is inconsistent with the preset model, a conveying mechanism is stopped or an alarm is triggered. However, the single verification mode has the obvious defects that the single verification is carried out only before a workpiece enters a grabbing station, the wrong grabbing caused by reasons such as workpiece stacking shielding, adjacent workpiece adhesion, grabbing position deviation and the like at the grabbing moment cannot be found, when a robot grabs a workpiece with an incorrect model according to a preset track, the robot can collide with a material frame or peripheral equipment severely due to the fact that the size and the shape of the workpiece are not consistent with the expected size and shape of the workpiece, equipment damage, production stop lines and even personnel safety accidents are caused, and the existing system stops the equipment only through software instructions when the existing system is abnormal, so that the accidents cannot be effectively prevented once a software program fails or communication is interrupted. Therefore, how to realize the whole flow monitoring of the robot grabbing process and prevent the collision accident caused by the error of the model of the workpiece becomes a technical problem to be solved in the field. Disclosure of Invention In order to solve the problems, the invention provides a robot grabbing anti-collision control method and a system for an automatic production line, which are used for preventing the problem that a robot collides when grabbing materials and safety accidents are caused because other vehicle-type blank parts are included in a feeding frame due to the fact that the feeding frame is subjected to the sequential omission detection. In a first aspect, the present invention provides a method for controlling a robot gripping anti-collision in an automatic production line, applied to a robot gripping system controlled by a line programmable logic controller, comprising the steps of: s1, when a trigger signal of a robot entering a grabbing track is received, a line body programmable logic controller sends a starting instruction to a code scanning gun, and the code scanning gun continuously acquires multi-frame two-dimensional code images at preset frequency in the process that a robot gripper moves to a workpiece in a material frame; S2, analyzing the multi-frame images in real time, extracting clear and readable two-dimensional code information frames, and analyzing to obtain first workpiece model data; S3, triggering and collecting again by the code scanning gun at the moment that the robot gripper contacts and grabs the workpiece, acquiring a two-dimensional code image at the grabbing moment, and analyzing to obtain second workpiece model data; S4, performing double comparison on the first workpiece model data and the second workpiece model data with target model data preset by the touch screen respectively; S5, if the double comparison results are consistent, sending a lifting permission signal to a robot control system, and controlling the robot to take out the workpiece from the material frame and transfer the workpiece to a processing station; S6, if any comparison result is inconsistent, immediately executing an emergency stop program: interrupting a robot grabbing program through a software instruction and triggering an audible and visual alarm; The physical isolation signal is output through an independent hard wire IO, and the safety relay coil connected in series in the robot grabbing power loop is cut off, so that the robot is kept in the current safety posture, and collision accidents are prevented. By collecting and analyzing the two-dimensio